Analog output time delay error in DasyLab 11 Pro to NI PCI-6251

[Ryan Wight]

Hi,

I am having issues with trying to get a proper analog output from DasyLab to the PCI-6251 board.

I have tried two different set ups. One that I created from scratch allows me to have a proper output, but my input data collection will only give me force data to two decimal places (only on halves though; ie. 0.1, 0.15, 0.20). This causes a very rough force tracing that is no good for data collection.

The other set up that I have tried was created from a previous worksheet that was used to collect input data only, without the output modules. This set up causes delays in my output, which doesnt allow me to stimulate the subjects at the proper timepoints.

Here are the two different set ups that I have tried. To open the files, save them to your desktop and open through DasyLab or else they won't work.

The old one, is the set up that produces the choppy data, whereas the new one produces the unwanted delay.

Thanks for your ongoing help.

-Ryan Wight

[Ryan Wight]

Currently my MAX settings for the Output task are:

Continuous Samples, 10k Samples to Read, 10k Rate

For the Input task:

Continuous Samples, 10k Samples to Read, 10k Rate

I've tried playing around with the input settings, as I would like to collect data at a sampling rate of 4k so that I have 2k per channel (Channel 1 = Force, Channel 2 = EMG). When I try this, I get an error message telling me the following:

CIT Output >>DAQmxWriteAnalogF64

Measurements: the generation has stopped to prevent the regeneration of old samples. Your application was unable to write samples to the background buffer fast enough to prevent old samples from being regenerated.

From what I've read, the easiest way is to increase the samples to read, which I've tried, to no success.

[Jake_G]

Hey Ryan,

You say that you have tried increasing your samples to read, have you tried any of these?

To avoid this error, you can do any of the following:

1. Increase buffer size

2. Increase number of samples you write

3. Write samples more often

4. Reduce the sample.

I found this in a similar discussion forum here.  Is this discussion similar to what you are seeing?